#include<iostream>
#include<stack>

using namespace std;

namespace zkz
{
	template<class T, class Con = deque<T>>
	class stack
	{
	public:
		stack()
		{};
		size_t size()
		{
			return _c.size();
		}
		void push(const T& x)
		{
			_c.push_back(x);
		}
		void pop()
		{
			_c.pop_back();
		}
		T& top()
		{
			/*auto it = _c.end()-1;
			return *it;*/
			return _c.back();

		}
		const T& top()const
		{
			/*auto it = _c.end() - 1;
			return *it;*/
			return _c.back();
		}
		bool empty()
		{
			/*return _c.size() == 0;*/
			return _c.empty();
		}
	private:
		Con _c;
	};
	
}